| 摘要 |
A structure of a laminated multilayer overlay 14 for plain bearings is provided. The structure consists of a group of soft metallic sub-layers 14a separated by hard intermetallic compound sub-layers 14b. The hard intermetallic layers 14b are developed by diffusion during heat treatment rather than by complicated alloying or chemical processes during deposition. The outer/top sub-layer provides protection during the running-in of an engine. The innermost sub-layer interfaces with an intermediate layer 13 and provides a good bond with a bearing lining layer 12. The hard layers 14b provide mechanical strength and Poisson constraint and help ensure the integrity of the coating. Also provided is a plain bearing comprising a backing layer 11, a bearing metal layer 12, an optional intermediate layer 13 and an overlay 14. The overlay 14 comprises a plurality of sub-layers 14a, 14b, the sub-layers comprising two or more relatively soft sub-layers14a and one or more relatively hard sub-layers 14b. The soft and hard sub-layers 14a, 14b are arranged alternately with respect to one another, each soft sub-layer 14a comprising a metal or metal alloy, and each hard sub-layer 14b comprising a one or more intermetallic compounds. A process for manufacturing such sliding overlays is also provided. |
